Strapless respiratory face mask

Abstract

The present invention relates to face masks to control and improve the quality of inhaled air. Claimed and described is a respiratory face mask comprising a flange and a filter layer, the flange having an inner periphery and an outer periphery and a first and a second width measured perpendicular to the inner periphery between the inner periphery and the outer periphery, characterised in that the first width is greater than the second width. Preferably, such face masks are strapless and rely on a hydrogel adhesive for attachment and sealing. Further claimed and described is an improved cover layer for an adhesive of such a face mask.

What is claimed is: 
     
       1. A respiratory face mask comprising:
 a flange adapted to fit on a face of a wearer and having an inner periphery and an outer periphery, said flange being symmetrical about a longitudinal axis defining left and right halves of the mask, said flange being wider at 0°, 90° and 180° relative to a central point on the axis than in sectors extending from 40° to 60° and 110° to 130°; 
 said flange having a wearer facing side and a garment facing side, said wearer facing side having a layer of a hydrogel adhesive having a dry initial peel strength (PDI) and a greasy initial peel strength (PGI), wherein a ratio of PDI to PGI is from 1:1 to 1.0:0.2; and 
 an air control module carried by said flange. 
 
     
     
       2. The mask of  claim 1 , wherein the ratio of PDI to PGI is from 1:1 to 1.0:0.3. 
     
     
       3. The mask of  claim 1 , wherein the PDI ranges from 0.1 N/cm to 5.0 N/cm. 
     
     
       4. The mask of  claim 3 , wherein the PGI ranges from 0.1 N/cm to 5.0 N/cm. 
     
     
       5. The mask of  claim 1 , wherein said layer has a thickness of C mm, wherein said adhesive has a viscous modulus C″25 (100 rad/sec) at a temperature of 25° C., and wherein G″25 (100 rad/sec)≦{(7.00+C)*3000} Pa. 
     
     
       6. The mask of  claim 5 , wherein G″25 (100 rad/sec)≦{(5.50+C)*1700} Pa. 
     
     
       7. The mask of  claim 1 , wherein said adhesive has an elastic modulus G′37 (1 rad/sec) at a temperature of 37° C. that ranges from 500 Pa to 20,000 Pa and a viscous modulus G″37 (1 rad/sec) at a temperature of 37° C. that ranges from 100 Pa to 15,000 Pa, and wherein a ratio of G′37 (1 rad/sec) to G″37 (1 rad/sec) ranges from 1 to 30. 
     
     
       8. The mask of  claim 1 , wherein said adhesive is a substantially water insoluble pressure sensitive adhesive comprising a polymer that forms a 3-dimensional matrix and less than 10% by weight hydrocolloid particles. 
     
     
       9. The mask of  claim 8 , wherein said adhesive comprises less than 5% by weight hydrocolloid particles. 
     
     
       10. The mask of  claim 1 , wherein said adhesive comprises a polymer selected from the group of polymers consisting of acrylics, sulphonated polymers, vinyl alcohol, vinyl pyrrolidine, polyethylene oxide and mixtures thereof; and a plasticizer selected from the group of plasticizers consisting of polyhydric alcohol, polyethylene glycol, sorbitol, water and mixtures thereof. 
     
     
       11. The mask of  claim 1 , wherein said air control module comprises means for stretching said air control module. 
     
     
       12. The mask of  claim 1 , wherein said sectors that are less wide extend from 30° to 70° and 105° to 140°. 
     
     
       13. The mask of  claim 12 , wherein said sectors that are less wide extend from 20° to 80° and 100° to 150°. 
     
     
       14. The mask of  claim 1 , wherein said flange is at least 10% wider at 0°, 90° and 180° than in said sectors. 
     
     
       15. The mask of  claim 14 , wherein said flange is at least 40% wider at 0°, 90° and 180° than in said sectors. 
     
     
       16. The mask of  claim 15 , wherein said flange is at least 80% wider at 0°, 90° and 180° than in said sectors.